The present application claims the benefit of the filing date of Canadian application no. 2,365,810, filed Dec. 21, 2001.
The invention relates to a plant growing system having a plurality of interconnected and elongated members for supporting growing plants. The system is preferably integrated with an irrigation system to provide a complete hydroponics system.
Hydroponic growing systems are well known in agriculture as effective growing systems. Generally, in a hydroponic system, growing plants are supported on a soil-less media and a nutrient solution is circulated through the media to provide both nutrients and water to the growing plant. The main advantage of a closed hydroponics system over traditional soil-based (irrigation) agriculture is that approximately 95% of the water which would otherwise normally be lost to the ground through permeation or to the atmosphere through evaporation can be retained within the system. As a result, growing plants often only require 5% or less of the water that would otherwise normally be required to grow viable plants.
In addition to the decreased water usage, hydroponic systems also address other problems associated with traditional irrigation agriculture including soil salination and over-use of fertilizers.
Soil salination due to over-irrigation has recently become a significant problem in the first world in areas such as California. This problem is generally caused by decades of irrigated water leaving salt and other mineral deposits in soil, which eventually accumulate to the point that crops cannot be economically grown in that soil.
Leaching of fertilizer into the environment is also a significant problem where fertilizers that have been applied to agricultural fields are washed into the stream and river systems with the result that aquatic life in the rivers is severely affected. As an example, fertilizer pollution originating from the Mississippi catch basin has resulted in an extensive dead zone (over 500 square miles in size) at the mouth of the Mississippi. In other areas, such as the east coast of Australia, large swaths of coral reef have been affected in a similar manner.
While significant problems have emerged and will continue to emerge with commercial agriculture in valuable growing regions, in many regions of the world (both first world and developing world) water supply, water quality and soil quality prevent effective agriculture. While hydroponic systems can and have been successfully deployed around the world, one of the biggest obstacles to widespread deployment has been the cost of the systems. In many instances, the cost has been a function of the design of these past systems where either of the capital or operating costs of the systems have prevented widespread deployment. For example, past systems using various support media including mineral wool (rock wool) or perforated styrofoam mediums require ongoing or regular replacement of the support media after each or a limited number of harvests. In addition, the cost associated with purchasing, transporting and disposing these media can be prohibitively expensive to many growers. Further still, such systems are disadvantaged as a result of the substantial energy and environmental costs which may be associated with the production and use of these media.
Other media, such as lava rocks or pebbles are heavy and while not presenting the same disposal problems are expensive to transport and are often affected by silting problems during use within the flooding system.
As a result, there has been a need for a hydroponic system that overcomes the problems of past systems by providing an effective support media that is economically efficient in terms of capital and operating costs while further providing a highly effective support media for growing plants. Moreover, there has been a need for a system that is environmentally superior to past systems both in terms of disposal of support media and the ability to recycle the support media. In particular, there has been a need for a system having a light weight support media that enables straightforward growth and harvesting of plants and that additionally enables the system to be efficiently readied for a new crop while continuing to have the water consumption benefits of past hydroponic systems.
A review of the prior art reveals that such a system has not been developed. For example, U.S. Pat. No. 2,639,549, U.S. Pat. No. 3,744,183, U.S. Pat. No. 4,403,446, U.S. Pat. No. 4,937, U.S. Pat. No. 4,037,362, U.S. Pat. No. 3,660,933, U.S. Pat. No. 4,467,561, U.S. Pat. No. 4,607,454, U.S. Pat. No. 5,983,562, U.S. Pat. No. 6,082,044 each disclose hydroponic systems but do not address the problems solved by the present invention.
In accordance with the invention, there is provided a plant growing system comprising:
a set of elongated members for supporting a growing plant wherein the spacing between elongated members allows passage of a nutrient solution around the elongated members.
In accordance with another embodiment, the system further comprises a corresponding second set of elongated members, the first and second sets of elongated members for supporting a growing plant wherein the spacing between elongated members allows passage of a nutrient solution around interconnected elongated members.
In one embodiment, the system includes a frame for supporting the first and second sets of elongated members which preferably includes openings for telescopically receiving individual elongated members of the first set of elongated members. The openings may be inwardly tapered to facilitate assembly of the elongated members within the frame and the elongated members may have a stop system to prevent removal of the elongated members from the frame after assembly.
The elongated members preferably have a circular cross section although any cross-sectional profile that allows elongated members to interconnect, allow the nutrient solution to circulate between or within the members and to support a growing plant may be utilized. The elongated members may also have a textured surface for retaining water. The elongated members may also be hollow and may be telescopically received in one another.
The plant growing system is preferably integrated into a hydroponics growing system, having an irrigation system for supporting and flooding the elongated members with the nutrient solution. In one embodiment, the irrigation system includes one or more pipes, each having at least one opening for allowing light access to a growing plant on the elongated members.
The elongated members may be any material suitable for growing a plant including plastics and metals. It is preferred that the elongated members are opaque to prevent light penetration to the root system of a plant.
The invention also provides a method of growing and harvesting plants comprising:
placing a seed or a plant on first and seconds sets of interconnected elongated members;
circulating a nutrient solution through the interconnected elongated members to promote plant growth; and,
opening the first and second sets of interconnected elongated members to remove grown plant material from the elongated members.